The mechanical washing of dishes is effected, as known, in several steps, generally called "cycles," where one or more intermediate rinsing cycles with clear water are arranged between the washing cycle proper and the final clear rinsing cycle in order to reduce the entrainment of dirty liquor. Generally two different agents are used for the washing cycle and clear rinse cycle, namely a dishwashing agent (cleanser) and a clear rinsing agent (clear rinse) (Ullmanns Encyklopaedie der technischen Chemie, 14 (1963) p. 656 and DOS 2,259,830).
The cleanser has the function of swelling the food residues during the washing cycle of the dishwashing machine, to detach them from the dishes, and to disperse them in the cleanser liquor.
In the last rinse cycle the dishes are rinsed with addition of the clear rinse agent. The clear rinse agent has the function according to its composition, on the one hand, of lowering the surface tension of the water so that it forms a closed film on the dish surface, which becomes increasingly thinner on runoff and which disappears finally, and on the other hand, to ensure that the dishes have a uniform shine after drying.
With the use of this combination of a cleanser and clear rinse agent, even delicate dishes are washed gently and satisfactorily and rinsed to a dry shine in modern dishwashing machines. But it is an inconvenience that it is necessary to use two different preparations to obtain a good result, which must in addition be specifically adapted to each other.